Hi, Shane, On 05/04/2011 04:22 p.m., Shane Amante wrote: > With respect to your comments on, both at the mic at the 6MAN WG and > on the list: draft-ietf-6man-flow-3697bis-02 > draft-ietf-6man-flow-ecmp-01 draft-ietf-6man-flow-update-04 > > You seem to take issue with a recommendation for creating/selecting a > flow-label that is "pseudo-random". Can you clarify the reason(s) > you take issue with creating/selecting a flow-label that is > "pseudo-random"? (IMO, the current 'SHOULD' in the draft provides > enough leeway that if implementations have good reason(s) to not > select pseudo-random values for flow-labels they can choose to do so, > but would hopefully have good reasons for that). > > The reason I ask is as follows: 1) RFC 6056: Recommendations for > Transport Protocol Randomization, in particular Appendix A. In > short, a lot of [deployed] implementations are already computing a > pseudo-random value for a transport protocol port (within the > ephemeral port range), today, so IMHO the implementation "burden" of > choosing a pseudo-random value must be quite low and, in theory, > there should be good re-use of that code/logic for selecting > flow-labels.
And even if they had to implement this support "from scratch", the code would be very small -- see e.g. the recent patch for port randomization that was posted to freebsd-net. > 2) If we expect that if a intermediate router or switch > is using *just* the 3-tuple of {src_ip, dst_ip + flow_label} as > input-keys to compute a load-balancing hash algorithm, then the more [...] +1 for pseudo-random Flow Labels :-) Thanks, -- Fernando Gont e-mail: ferna...@gont.com.ar || fg...@acm.org PGP Fingerprint: 7809 84F5 322E 45C7 F1C9 3945 96EE A9EF D076 FFF1 -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------